For example, a solenoid-controlled valve for switching a passage of compressed air is usually provided with a manual operation mechanism so that the switching operation can be performed manually in the event of an emergency such as service interruption. The manual operation mechanism has generally one or a plurality of plunger-type operating pieces. By pushing the operating piece, the solenoid-controlled valve is switched.
The operating piece is provided either in a state where it is recessed in the body of a valve or in a state where it is projected to the outside. In the former case, since the operating piece is recessed, there is an inconvenience such that the switching operation has to be performed by using a tool such as a driver. Recently, therefore, the operating piece is often provided in a projected state as the latter case.
When the operating piece is provided in a projected state, although the switching operation can be performed easily by only a finger without using a tool, the operating piece is inadvertently pressed by being touched by a hand or other foreign matter and misoperation is easily caused.
It is therefore necessary to take a measure by attaching, for example, a safety cover to the operating piece. Since the operating piece is small, the safety cover is naturally small and a work to attach or detach the safety cover is not easily. Especially, the cover is requested to be securely retained by the operating piece and not to be easily detached due to vibration or the like when it is attached to the operating piece. It is also requested to be easily attached or detached only by fingers at the time of attachment and detachment. It is also requested that the cover detached is not lost in the case such that the cover is detached and the operating piece is manually operated. A solenoid-controlled valve having a cover which can satisfy all of the requests is not conventionally known.